This study concentrates on the long term effects of alcohol which was consumed during the early stages of development. The effects on the gamete, on the zygote, on the embryo, and on the postnatal development are being followed. The study uses two distinct genotypes in which fertilizer ova from alcohol treated mothers are transferred to untreated host mothers and ova from untreated mothers are transplanted into the uteri of alcohol treated mothers. Similarly, cross-fostering between alcohol treated mothers and untreated mothers is used for each strain and each intra-uterine treatment group to study those effects attributable to alcohol during lactation with and without interaction with previous alcohol exposure. Physical growth, development, behavioral normality, and physiological normalcy are being monitored, as indicated in the proposal, with the objective of detecting any departures from control levels attributable to alcohol. Effects on prenatal as well as postnatal development are being monitored. Those variables which are effected by alcohol are being studied further in order to determine both the nature of the modifications induced and the critical time during development when the initial departure from normality can first be detected. Studies of the biochemical mechanism will follow. The same paradigm is being evaluated for future studies using drugs, pollutants, and other biologically active agents.